Heavy duty construction machines such as loaders, tractors, bulldozers, excavators, ground movers and the like generally comprise a machine frame, a work implement mounted to the machine frame and an internal combustion engine to power the work implement. A cooling system may be provided for cooling the engine, the cooling system typically comprising a radiator and a fan enclosed within a housing or cover. The fan may be driven hydraulically, electronically or mechanically via a belt system.
The radiator may be mounted on the machine frame next to the engine. In some machines the cooling fan is located outboard the radiator. The fan pulls cooling air through the radiator for engine cooling purposes, and the air is discharged through the fan grill.
In other machines the fan is located between the radiator and the engine. The fan pushes cooling air through the radiator for engine cooling purposes, and the air is discharged through air exhaust ports typically formed in the cooling system housing.
The fan may be rotatively driven by a hydraulic pump working off the engine, or the fan may be belt driven using a fan belt that works off the engine.
Some cooling fans are located within a circular opening in an aperture plate. Aperture plates are low cost, but they have significant disadvantages in terms of sound emissions, power requirements and fuel consumption. For example, aperture plates have a knife edge that can disrupt the flow of air through the fan.
The present disclosure is directed toward one or more of the problems set forth above.